The invention relates to a process for the preparation of alkylenebis(2-pyridylamine) compounds of formula I ##STR1## in which each R is independently H or C.sub.1 -C.sub.6 -alkyl and n is 2-8. The invention also relates to Karl-Fischer reagents containing a compound of the general formula I used for the determination of water content within a sample.
A preparation process for compounds of the general formula I is known from J. Chem. Soc. 1938, 1191-1193. There alkylenebis(2-pyridylamine) compounds are prepared by reacting 2-aminopyridine with dibromoalkanes in the presence of sodium amide in toluene as solvent.
However, the known synthetic process has a number of disadvantages. Thus, for example, the yields for lower alkylene radicals are unsatisfactory, the solvents used are a potential health risk and byproducts are formed which are very volatile and whose structure is not known.